Mesosignum weddellensis sp. nov. (Crustacea: Asellota: Mesosignidae), a new isopod species from the abyssal Weddell Sea, Antarctica

Zootaxa ◽  
2004 ◽  
Vol 501 (1) ◽  
pp. 1
Author(s):  
MADHUMITA CHOUDHURY ◽  
ANGELIKA BRANDT
Keyword(s):  
Pacific Ocean ◽  
Southern Ocean ◽  
Weddell Sea ◽  
The Other ◽  
Similar Species ◽  
The Pacific ◽  
Significant Difference ◽  
The Pacific Ocean ◽  
Species Being

Mesosignum weddellensis sp. nov. is described from the abyssal Weddell Sea, Antarctica. This is the second record of Mesosignum from the Southern Ocean, the other known species being M. antarcticum Schultz, 1979. Mesosignum brevispinis Birstein, 1963 from the Pacific Ocean is the most similar species. The most significant difference is the length of the seventh pereonite, which is only half as long as the other pereonites in M. brevispinis, while in M. weddellensis it is as long as the other pereonites.

A new species of Mysidium (Peracarida: Mysida: Mysidae) from the eastern tropical Pacific

2016 ◽  
Vol 97 (1) ◽  
pp. 113-117
Author(s):  
Manuel Ortiz ◽  
Michel E. Hendrickx ◽  
Ignacio Winfield
Keyword(s):  
New Species ◽  
Pacific Ocean ◽  
Tropical Pacific ◽  
The Other ◽  
Eastern Tropical Pacific ◽  
The Pacific ◽  
Appendix Masculina ◽  
The Pacific Ocean ◽  
A New Species

A new species of Mysidium from the eastern tropical Pacific, Mexico, is described, representing the second species of this genus described for the Pacific Ocean and the eighth species reported worldwide. Mysidium pumae sp. nov. is distinguished from the other species of the genus by several characters including: the lanceolate appendix masculina, 3× as long as wide, tapering distally, with a distal tuft of 16 setae and an inner proximal tuft of more than 30 setae, the male pleopod 4 with endopod bearing 3 setae, the exopod with 4 articles, the modified seta from article 3 of the exopod bifid, telson 2.3× as long as wide, distally concave. A table with the main differences among all the known species in the genus is provided.

Taxonomy and biogeography of Molgolaimus Ditlevsen, 1921 (Nematoda: Chromadoria) with reference to the origins of deep sea nematodes

2006 ◽  
Vol 18 (1) ◽  
pp. 23-50 ◽  
Author(s):  
Gustavo Fonseca ◽  
Ann Vanreusel ◽  
Wilfrieda Decraemer
Keyword(s):  
Deep Sea ◽  
Tail Length ◽  
Species Level ◽  
Weddell Sea ◽  
Similar Species ◽  
Disturbed Areas ◽  
The Pacific ◽  
Morphometric Features ◽  
Total Community ◽  
The Pacific Ocean

Molgolaimus is a genus of free-living marine nematodes which is found in high densities (10–35% of the total community) up to 2000 m depth. Its occurrence is often associated with organically enriched and recently disturbed areas. Currently, only 16 species have been described, mainly from shallow waters. The present study contributes 17 new species mainly from the Weddell Sea but also from the Pacific Ocean, and provides an illustrated polytomous identification key to species level. The 33 Molgolaimus species described can be identified based on just a few morphometric features: spicule length, body length, anal body diameter, tail length and pharynx length. A first insight into the biogeography of this deep sea genus at species level is presented. A comparison of morphometric characteristics between species suggests that the most similar species co-occur in the same geographical region, rather than within the same bathymetric zones or similar ecosystems separated over long distances. These observations suggest that deep sea nematodes may not have a common origin but might have derived “recently” from shallow water taxa. Therefore, global distribution of nematodes could be explained by means of palaeogeographical events.

Acid secretion in the Pacific Ocean gastropods

1969 ◽  
Vol 17 (5) ◽  
pp. 755 ◽  
Author(s):  
TE Thompson
Keyword(s):  
Electron Microscope ◽  
Pacific Ocean ◽  
Acid Secretion ◽  
Sulphuric Acid ◽  
Epidermal Cell ◽  
Goblet Cells ◽  
The Other ◽  
The Pacific ◽  
The Pacific Ocean ◽  
Similar Appearance

Acid secretion is recorded for 22 species of Pacific Ocean gastropods. Pleurobranchus peroni, Cypraea clandestina, C. spadicea, and Lamellaria sp. were investigated in detail. It was established that the "empty" epidermal cells of P. peroni elaborate and secrete the acid and it is suggested that cells of similar appearance in the other species have the same function. The acid is discharged, following abrupt disturbance, by rupture of the epidermal acid cells in most species, but through permanent pores in Lamellaria sp. Tests suggest that the secretion is predominantly sulphuric acid. The structure of the epidermal acid cells was investigated with the electron microscope and the formation and coalescence of acid vacuoles are described. A second type of epidermal cell, found in P. peroni and C. spadicea, contains longitudinally striated material and is believed to play a mechanically supporting role. Mucous goblet cells and sparse epidermal cilia were also identified in various species.

Description of two new species of munnopsid isopods (Crustacea: Isopoda: Asellota) from manganese nodules area of the Clarion-Clipperton Fracture Zone, Pacific Ocean

Zootaxa ◽  
2011 ◽  
Vol 2783 (1) ◽  
pp. 1 ◽  
Author(s):  
MARINA V. MALYUTINA
Keyword(s):  
New Species ◽  
Pacific Ocean ◽  
Fracture Zone ◽  
Similar Species ◽  
Manganese Nodules ◽  
The Pacific ◽  
Clipperton Fracture Zone ◽  
Two New Species ◽  
The Pacific Ocean ◽  
Clarion Clipperton Fracture Zone

Two new species of deep sea asellotes of the family Munnopsidae, Rectisura slavai sp. nov. and Storthyngura yuzhmorgeo sp. nov. are described from the manganese nodules area in the Clarion-Clipperton Fracture Zone of the Pacific Ocean. The discovery of these new species allowed re-examination of the taxonomic position of two similar species, Storthyngura ? intermedia (Beddard, 1885) from the Northeastern Basin of the Pacific Ocean and Ilyarachna defecta Menzies & George, 1972 from the Peru-Chile Trench, eastern Pacific Ocean. The species are moved to the genera Rectisura Malyutina, 2003 and Storthyngura Vanhöffen, 1914, respectively. Additional composition and distribution of the species of the genera are presented.

First finding of anchialine and submarine cave dwelling brittle stars from the Pacific Ocean, with descriptions of new species of Ophiolepis and Ophiozonella (Echinodermata: Ophiuroidea: Amphilepidida)

Zootaxa ◽  
2018 ◽  
Vol 4377 (1) ◽  
pp. 1 ◽  
Author(s):  
MASANORI OKANISHI ◽  
YOSHIHISA FUJITA
Keyword(s):  
New Species ◽  
Pacific Ocean ◽  
The Other ◽  
Ryukyu Islands ◽  
Uniform Size ◽  
First Finding ◽  
The Pacific ◽  
The Ryukyu Islands ◽  
The Pacific Ocean ◽  
Submarine Cave

Two new species, Ophiolepis cavitata n. sp. and Ophiozonella cavernalis n. sp., are described from the specimens collected in shallow water submarine caves in the Ryukyu Islands, southwestern Japan. Ophiolepis cavitata n. sp. is distinguished from the other congeners in having prominent tubercle-shaped knobs on dorsal arm plates; two sizes of disc scales on the aboral disc, the larger surrounded by 3–8 times smaller disc scales; larger scales concave; radial shields wider than long; a trio of distinct scales present distal to each pair of radial shields; oral shields partly concave; 3 arm spines on proximal portion of the arms. Ophiozonella cavernalis n. sp. is distinguished from the other congeners in having polygonal, uniform size disc scales; oral shields almost as long as wide, shallow concave proximal sides that end in a fairly sharp point medially; arms about 9 times longer than disc diameter; 3 cylindrical arm spines, of which the oral most one is slightly larger than other 2 spines. Ophiozonella cavernalis n. sp. is the second finding of an anchialine-endemic ophiuroid and the first finding from the Pacific Ocean. 

Description of three new species of Bradyidius (Copepoda: Calanoida), the new aetideids from the deep Pacific Ocean, with notes on the genera Bradyidius and Aetideopsis

Zootaxa ◽  
2021 ◽  
Vol 5004 (2) ◽  
pp. 343-369
Author(s):  
ELENA L. MARKHASEVA ◽  
JASMIN RENZ
Keyword(s):  
Pacific Ocean ◽  
Atlantic Ocean ◽  
World Ocean ◽  
Weddell Sea ◽  
Lateral Spine ◽  
The Pacific ◽  
The Pacific Ocean ◽  
Three New Species ◽  
Argentine Basin ◽  
Exopod Segment

Three new aetideid species, Bradyidius abyssalis sp. nov., Bradyidius parabyssalis sp. nov., and B. kurilokamchaticus sp. nov. are described from female specimens collected near the seafloor in the abyss of the Pacific and Atlantic Oceans. Specimens of Bradyidius parabyssalis sp. nov. were obtained in both the Atlantic and Pacific Oceans (Argentine Basin, area of the Meteor Seamount and the Kurile-Kamchatka Trench). Bradyidius abyssalis sp. nov. was found only in the Atlantic Ocean, (Brazil and Guinea Basins and area of the Meteor Seamount) and Bradyidius kurilokamchaticus sp. nov. was recorded from the Kurile-Kamchatka Trench of the Pacific Ocean. Three new herein described Bradyidius species constitute the first documented records of the genus from the abyss of the World Ocean. In addition, three Bradyidius species from the Weddell Sea, the Atlantic Ocean and the Kurile-Kamchatka Trench, are briefly described without biological names due to their bad condition. Bradyidius parabyssalis sp. nov. and B. abyssalis sp. nov. are distinguished from all known congeners by the presence of 3 setae at the basis of the mandible and morphological details of the prosome posterior corners and P1. They show close resemblance to each other but differ in body size, rostrum structure, P4 coxa armament and length of the setae of the antennule ancestral segment I and the mandible basis. Bradyidius kurilokamchaticus sp. nov. shares with B. curtus Markhaseva, 1993, B. pacificus (Brodsky, 1950) and B. arnoldi Fleminger, 1957 a rostrum with non-divergent or parallel points, but differs from these species in the size, the well developed lateral spine on exopod segment 1, in the number of setae at the antenna exopod segment 1 and some morphological details of the prosome posterior corners. Characters that define the genus Bradyidius Giesbrecht, 1897 from Aetideopsis Sars, 1903, i.e. the shape of lateral spines of P1exopod segments 1 and 2; the endopod of P2 segmentation and the setation of the antennule ancestral segments XII, XV and XVII are discussed.

SOME FURTHER RECORDS OF PELAGIC POLYCHAETA FROM THE NORTHEAST PACIFIC NORTH OF LATITUDE 40° N. AND EAST OF LONGITUDE 175° W., TOGETHER WITH RECORDS OF SIPHONOPHORA, MOLLUSCA, AND TUNICATA FROM THE SAME REGION

1960 ◽  
Vol 38 (4) ◽  
pp. 787-799 ◽  
Author(s):  
E. Berkeley ◽  
C. Berkeley
Keyword(s):  
Pacific Ocean ◽  
New Records ◽  
The Other ◽  
Pacific Region ◽  
Northeast Pacific ◽  
The Pacific ◽  
Northeastern Pacific ◽  
The Pacific Ocean

Seventeen species of pelagic Polychaeta from the northeastern Pacific are recorded. Of these, five (Sphaerosyllis pirifera Claparède, Dorvillea kefersteini McIntosh, Spiophanes cirrata Sars, Magelona sp., and Flabelligera affinis Sars) are species which, whilst not exclusively pelagic, are known to swim at some stage, particularly as larvae. One record (Pedinosoma curtum Reibisch) is new to the Pacific Ocean, two (Pontodora pelagica Greef and Callisona nasuta Greef) are new to the northeastern Pacific region, and four (Pelagobia longicirrata Greef, Lopadorhynchus uncinatus Fauvel, Sagitella kowalewskii Wagner, and Callizona angelini (Kinberg)) are records of northerly extensions of distribution. The first observation of a larval Cossura (probably of C. longocirrata Webster and Benedict) is recorded. Poeobius meseres Heath is recorded from a number of stations and the classification of Poeobiidae is discussed.Eight species of Siphonophora are listed, all of which constitute new records for the region covered by the present collections. Six species of Mollusca, comprising five Pteropoda and one Heteropoda, are recorded, none of which have been identified previously in northeastern Pacific plankton. Three of the genera of Pteropoda (Anopsia, Thliptodon, and Cliopsis) are characteristic of warmer seas, the other two, and the heteropod, are widely distributed. Of the two species of Tunicata listed one is new to the northeastern Pacific.

Kelvin Waves around Antarctica

2014 ◽  
Vol 44 (11) ◽  
pp. 2909-2920 ◽  
Author(s):  
Kazuya Kusahara ◽  
Kay I. Ohshima
Keyword(s):  
Pacific Ocean ◽  
Southern Ocean ◽  
Sea Level ◽  
Statistical Significance ◽  
Phase Speed ◽  
Drake Passage ◽  
Kelvin Waves ◽  
The Pacific ◽  
The Pacific Ocean ◽  
The Antarctic

Abstract The Southern Ocean allows circumpolar structure and the Antarctic coastline plays a role as a waveguide for oceanic Kelvin waves. Under the cyclic conditions, the horizontal wavenumbers and frequencies for circumpolarly propagating waves are quantized, with horizontal wavenumbers 1, 2, and 3, corresponding to periods of about 32, 16, and 11 h, respectively. At these frequencies, westward-propagating signals are detected in sea level variation observed at Antarctic coastal stations. The occurrence frequency of westward-propagating signals far exceeds the statistical significance, and the phase speed of the observed signal agrees well with the theoretical phase speed of external Kelvin waves. Therefore, this study concludes that the observed, westward-propagating sea level variability is a signal of the external Kelvin waves of wavenumbers 1, 2, and 3 around Antarctica. A series of numerical model experiments confirms that Kelvin waves around Antarctica are driven by surface air pressure and that these waves are excited not only by local forcing over the Southern Ocean, but also by remote forcing over the Pacific Ocean. Sea level variations generated over the Pacific Ocean can travel to the western side of the South American coast and cross over Drake Passage to the Antarctic continent, constituting a part of the Kelvin waves around Antarctica.

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